I need to install a combination power and low voltage box in the ceiling of my finished basement for my home theater projector. I can't bolt the projector mount directly to the studs because of alignment issues so I have to first install a 3/4" MDF or wood panel across the joists on top of the drywall. The projector mount will then be attached to the panel which will have plenty of space available for me to add the required rework box.
My question is, should the rework box be installed through the panel and the drywall or should it be attached to the drywall with a simple cutout through the panel? I believe code says that the box can be no deeper than 1/4" from the surface so I may already have my answer. I'm in Canada so I'm not sure if code is different here. Also, I'm not sure if there is an issue installing the box in MDF to begin with. I can always go with a piece of oak or pine.
Any guidance would be appreciated! Thanks!